1. Field of the Invention
The present invention mainly relates to a method of manufacturing an absorbent article used in incontinence pads, sanitary napkins, panty liners, medical pads, toiletries, disposal diapers and the like, and a method of manufacturing an absorbent article including an absorbent body having a concave groove formed at a top surface thereof along a longitudinal direction thereof.
2. Description of the Related Art
In conventional absorbent articles, an absorbent body is provided between a liquid impermeable backsheet, such as a polyethylene sheet or a non-woven fabric made of laminated polyethylene sheets, and a liquid permeable topsheet, such as a non-woven fabric or a permeable plastic sheet.
This kind of absorbent article has been improved many times, and various means are provided in order to prevent leakage of body fluid. As one of the means to prevent leakage of body fluid, a technique is provided to form a concave groove by heat embossing. For example, Patent Document 1 describes an absorbent article for increasing absorbance and retaining characteristics of liquid or the like, and suppressing or preventing flowback or leakage of the liquid or the like by quickly transferring the liquid or the like once absorbed to inside an absorbent body. For such purposes, Patent Document 1 describes a middle high portion formed by an upper absorbent layer and a lower absorbent layer provided with a groove formed in a skin contacting side and extending in a longitudinal direction of the absorbent article. The groove is an opening portion penetrating through the upper absorbent layer, and the lower absorbent layer is located under the lower surface of the upper absorbent layer so as to form a bottom surface of the opening portion. Further, Patent Document 2 describes a ladies' incontinence pad capable of suppressing swelling of an absorbent body near a standing gather due to absorption of urine by the absorbent polymer, by forming emboss processed portions along the standing gather near the inside of the standing gather of the absorbent body and at a using surface side of the absorbent body. Further, Patent Document 3 describes an absorbent article including a liquid permeable topsheet made of a sheet provided with a plurality of openings or a non-woven fabric. The absorbent article includes a center emboss, which is a concave groove, formed in the absorbent body from an upper surface of the liquid permeable topsheet and side embosses on both sides of the center emboss. The center emboss is processed after the side embosses are formed as a post-treatment so that the concave groove is formed at a center emboss processed portion while the liquid permeable topsheet is stretched and the opening of the topsheet is enlarged or the spaces between the fibers of the non-woven fabric are enlarged at the center emboss processed portion.